Sunday, January 11, 2015

Hey Grinderguy, should I use a Trommel or Star Screen?

Good Question.
The first question is what are you going to use it for? Topsoil, Compost, Mulch or something else?
The number one reason star screens became so popular was the ability to screen wet, damp materials. Because the stars are pliable, it is more difficult for material to build up on them and the speed of the rotating stars lessen the time material has a chance to build up on them.
Trying to screen wet compost or soil with a trommel screen is near impossible. Material builds up on screens and the framework of a trommel drum, choking off the screen openings and lessening the open screen area of the trommel drum. This makes screening ineffective. While the screen cleaning brushes on a trommel help with some damp products, the really moist materials are too much for them to work effectively.
This particular customer is a contractor that sells some topsoil and mulch also. Screening material on a job site to remove some larger stone or stump debris is not what a Star Screen is for. It works great screening sand and dirt out of landclearing grindings, but when you need to cleanup a jobsite, a trommel takes much more abuse and is much more versatile in these types of applications.
So, with common products, what screens are most effective?
Yard Waste Compost- Usually dry enough for a Trommel
Mulch- Can screen most any size
Topsoil- Works very well for this as long as it is dry
Aggregate- Can screen some aggregate
Star Screens:
Moist/Wet Materials- Sludge Compost for example
Mulch- Can screen fines or overs
Soil Blends- Soil Compost mixes, not so much straight topsoil
Compost- Very Productive compared to Trommels
No Aggregate

The downside of the Trommel is the need to inventory different screens or entire drums for different product sizes. With the Star Screen, motors drive the star shafts and just by changing speeds, different product sizes are created. While electric motors create a much greater range of product sizing than hydraulic models, there is a top and bottom size limit. Because of this range of size options, the product quality with a Star Screen is much better than the trommels. Hope this helps solve your dilemma.

Questions? Dave Whitelaw GrinderGuy

The GrinderGuy takes on Pine Bark

                Over the past year or so, I have had several questions about screening, grinding or cleaning up pine bark. For the past half century or more, pine bark was debarked at lumber mills and run across stationary shaker screens splitting large nuggets, mini-nuggets and pine bark. As typical with shaker screens, if over fed with material, contamination of products occurs. But, this is just the way it has been forever.
                With the reduction of lumber production the past 7-8 years, pine bark has been in short supply.  To keep fulfilling landscape product orders, mills started trying to recover pine from old piles scattered about their sites. These piles had logs, stone and a mix of pine bark and fines pushed up into them.
                A year or so ago, I was asked to screen one of these piles.  I took a 3 product star screen to try and screen and recover some of the pine bark. Depending on the size of the unit, I used a Komptech L3 and Komptech XXL, production could be from 250-400 yards an hour. By being able to adjust speeds of the stars by the touch of a button, I was able to create:
·         Overs
·         3” or 4” large nuggets
·         1 ½” or 2’” mini nuggets
·         Pine mulch from 3/4” down
·         Pine fines of 3/8”- 1/4”
Because I only had a 3 product machine, scalping overs and making large nuggets was easy, but the mini-nuggets were mixed with pine much and pine fines. By running the 1 ½” product back through, we were able to split the pine mulch from the mini-nuggets and if the customer wanted the pine mulch in the mini-nuggets, with a touch of a button, it was done. On one demo, I used an additional screen, a Komptech Easy Star, and was able to create 4 products by splitting the pine mulch, ¾” minus, from the 1 ½” mini-nuggets at the same time.
One of the major problems with pine bark supply is typically suppliers sell twice as many mini-nuggets as large nuggets. A request was made to grind the large nuggets into mini-nuggets. In a typical horizontal, tub or stationary grinder, the speed of the grinder is way too fast and turns the soft pine bark to pine dust. We decided to try a low speed shredder, a Komptech Crambo, which has screens for product size and has adjustable shaft speed. By slowing the shaft speed 50-60% and using 7” screens, we were able to reduce the large nuggets and create mini-nuggets without creating too many fines.
                A call I received just last week, had a customer trying to recover an old pine bark pile. They were screening with a deck screen, but the 1 ½” mini-nuggets had rock in it from all the extra materials pushed into the pile over the years. A rock goes through a 1 ½” hole just like a piece of pine bark does. The good thing is, they do not weigh the same. We took a portable air knife, a Komptech Stonefex, and ran the conveyor from the deck screen right into it. By adjusting the airflow of the Stonefex, were able to use the air to push the lightweight pine bark to one conveyor, while the heavier rock fell onto another conveyor. We were about 95% effective in removing the rock from the pine bark. A totally acceptable result.
After the time we spent the past year on the pine bark, I said “Why can’t we use a star screen in place of the shaker decks of old?” It does way more production. It is much more adjustable for product sizes. It is inexpensive operate and the cost is insignificant if it produces results in profits. We are now installing our first star deck system for pine bark in a new lumber mill.
Now, you DO NOT have to use the same machines I used. You can try any machine. It doesn’t cost you much. Each of these machines work on mulch the same way they work on pine bark. You just have to try them! The ways of old are not always the best. The best productivity equals profitability.
Questions? Want to try something? Contact me, Dave Whitelaw

Hey GrinderGuy, should I attend all these Trade Shows and Conferences?

I ask myself the same question about 10 times a year. It is painful spending the time away from your business. But how do you know what else is out there that may help your business grow? Everything you want and more is available at these Trade Shows.
Are you interested in a vacation or an education? Either way, make your time worthwhile.
First, figure out what you want to accomplish while attending these Conferences:
·         Are you looking for new business?
·         Are you looking for new equipment?
·         Are you looking for a better way?
Decide which Conferences are the best fit for your needs:
·         Most of the major trade shows are held in vacation destinations. If you are looking for a break and just want to see what is new in equipment and support industries, this is the way to go. You can see the newest machinery upgrades and new models all while taking time to smell the roses and take a break.
·         If you are looking for an education, most of the National Industry Organizations are the best for learning best practices, legal aspects and new improvements in sales and operations. Most of these Conferences are organized into tracts that can help you maximize your time to attend and a lot of the speakers are hands on in these Industries. For keeping up with all the Governmental regulations, these types of conferences are a must.
·         For making the best business and local contacts, your State Organizations are your best bet. All these people are your neighbors, in the same or similar business, and can be your supplier or your customer. Just starting out, this is where you want to go. You can get business advice, regulation knowledge and find support from others that used to be as new as you.
While at these Conferences, take the time to tour the Vendor Booths:
·         You may see something you never thought about, maybe a new improvement, maybe an idea from another industry?
·         See the latest and greatest in equipment
·         Speak with Engine Manufacturers of your equipment and learn how to maintain and check your engines or make them last longer
·         Software vendors are now at all Trade shows- Accounting, Transportation Software, Equipment Software that tracks production and relays all the information to the web for you to see in your office
·         Remote Control manufacturers are making operations more and more simple
·         Improvements on one manufacturer you see that can be added to your machine
It may take you away from your business for a while but what you gain can help you become more profitable, more productive and will give you a little break.

Questions? Dave Whitelaw GrinderGuy

Grinder fires can cost you

Grinder fires can cost you
The past month or so I have had two customers have grinders burn to the ground. Neither of the grinders was one of mine, but it affected my customers greatly.
Getting a call that your grinder has burned gives you a sickening feeling. I know, it happened to me.
Not only do you lose the use of your grinder, your insurance costs will surely increase and waiting for the insurance investigation and payment of coverage will further delay the replacement of your equipment. In these Industries, fires are always a possibility, so using some standard operating procedures will help reduce your chances of your equipment catching fire. Sometimes things are out of your control, but in most cases, housekeeping is the issue.
An air compressor is a necessary tool for every grinder operation. Even a leaf blower can be used in a pinch.
How can these fires happen:
·         Material Buildup on engines and exhaust systems
·         Hot metal that has been discharged from the grinder
·         One major issue is cracks in the muffler or exhaust systems. Mufflers not only reduce the noise of the engine, they actually capture sparks and disperse them prior to exhausting into the atmosphere. When cracks develop, the sparks can be sent out into the engine compartment. In addition, all the rust particles in the exhaust system get hot and are set out of these cracks to settle and burn themselves out somewhere.
·         Bearings failing create a lot of heat and can start fires
·         Exhaust air can also catch material on fire

What can you do? Standard operating procedures should include:
·         Blow off equipment daily with an air compressor, even with leaf blower if needed. This includes the radiator, hydraulic cooler, fuel cooler, air filter, etc.
·         Portable machines should be moved out of place, the area cleaned, then the put back in place. This will remove any surrounding debris and any hot metal that may be in the area
·         Face the discharge the furthest away from wind. For example, if wind is from the west, then the feed hopper or tub is the furthest west and the discharge is the furthest part of the machine east. This eliminates the ground materials from blowing back onto the machine.
·         Use a hopper or bin to collect metal debris
·         Use exhaust wraps or blanket to keep debris off exhaust system and heat controlled
·         Shutdown equipment at least an hour before you leave the site. This isn't an exact science because when it happened to me, the grinder had sat for two hours before I left the site. An hour and a half later, I had no grinder.
·         Use a Fire Suppression System. See my previous article about fire suppression systems.

                Also , in warm climates, you could face the radiator and coolers into the wind as long as the discharge of material is carrying opposite he radiator. This not only helps keep the engine cooler, it help the fuel cooler keep the fuel cooler which as we have talked about in the past, reduces your fuel usage.

Be smart, if the wind is blowing the material back over the machine, don't be a dumb grinder guy, you are just asking for a fire.

You may have other ideas. Turn them into a SOP List and have your operators stick to it. It's the best you can do to not lose $500,000 or more.

Dave Whitelaw, The Grinder Guy

Hey GrinderGuy, how much fuel does a Tub Grinder Use?

This customer was given numbers from 5 gallons per hour to 25 gallons per hour for a business plan.
First, thanks for the question, but I cannot realistically give you an exact answer. It is difficult to give an exact number because we never know what you are grinding 100% of the time and how fine you are grinding the material, but I can give you an idea and you could probably narrow it down to something close. But the 5 gallon an hour you were told must have been just idling time!
For this example, we will use the larger tub grinder engines supplied by Caterpillar®. I am not trying to single out one manufacturer, rather just using a Manufacturer of which I am familiar with using their engines. All the information I found on the web and can be related to any other manufacturer. You just need to do the homework.
So, for the larger tub grinders, and horizontal grinders for that matter, the basic engines are C18, C27 and C32. What do these numbers stand for? Basically this is the size of the engine, 18 liter, 27 liter and 32 liter. We will concentrate on the C18 engine model mostly because I am very familiar with it and because it is used in a variety of applications and comes in several horsepower ranges.
I downloaded three specification sheets for the C18 from the Caterpillar® website. I put the web addresses to download them here:
Industrial Engine Ratings Guide (Tier 3)-
I condensed the Tier 4 Ratings sheets into one table below. These may not be the exact engines used in the Grinder/Chipper applications, but will serve as a good example of what to ask questions about regarding specifications.
Speed Range- Tier 4 Caterpillar® C18*   
Speed RPM
Full Load Run Time
*All data is approximate. Contact your Local Engine Dealer for exact specifications

These combined sheets show that the C18 engine will go from 600-800hp based upon the rating. The ratings are based upon the maximum allowable 100% full load horsepower time. Basically, how long are you running at maximum horsepower? The combined Speed Ratings chart shows that if you are running at 100% full load all the time, like you would with a grinder, you can only use a 600hp rating on a C18 Engine. If you want to run at 700hp, you can only run at full load 50% of the time. Exceeding this will not only void your warranty, but probably blow/wear out the engine very quickly. Check with your Dealer for verification. But, how do they know? The computer logs engine loads as well as fuel usage. So divide the fuel usage by the number of hours on the engine and they know how hard you are pushing the engine.
                With the advent of computer controlled feed systems, in wood grinders and chippers, in the past ten years, manufacturers have maximized the loads put on the engines, keeping them at full load most all the time for maximum production. I run C18's allot in my 9 to 5 job. All my C18 units I run are at an A rating of 600 hp because we are using full HP “ALL THE TIME!” If you are running at 90% load, you are losing production.
So what does all this mean?
The referenced specification sheets do not show maximum fuel usage per rating, but obviously fuel rates increase as horsepower increases. The most fuel I ever used in my application is about 20 gallons per hour and that is from an A rating. I would venture a guess to say that maximum fuel for an A rating would be about 25-28 gls/hr range. As you move to the B, C and D ratings, you would increase to 35-40 gallons an hour at the least. Get the exact numbers from your local engine Dealer.
Because you cannot run at full load all the time, for example the tub stops spinning to let the engine catch up or the horizontal grinder stops the infeed of material , you cannot reach that max fuel number. But the harder you run, the closer you get to the max fuel number. Regrinding for example with the tub spinning as fast as it can will keep you near full load most all the time and close to that maximum fuel number. As you step up in engine size, so does the maximum fuel rates, so you can use those Dealer supplied numbers to figure out approximately how much fuel you will use.
One thing is for certain, it is not 5 gallons per hour! Can you imagine if this customer had based a business plan on 5 gallons per hour?
Your salesman will have all the specifications you will need for engine ratings and fuel consumption. If not, they certainly will have access to them.
So, in conclusion, do you homework. Do not just take one person’s answer or opinion as fact. Including mine.
Dave Whitelaw
Grinder Guy

Hey Grinderguy, how do I start a Mulch Business?

This call could have come from anyone, but it came from a Tree Service more or less.
Many Tree Service businesses get into a situation where their disposal costs are so high, that they have to find another avenue to make their waste disappear. While buying a half million dollar grinder does not sound like saving money, it may be. This customer was spending about $50,000 a year in disposal costs. While this is a significant amount, I wouldn’t necessarily say enough to warrant purchasing a grinder just yet. But how would you start is the question. What to do?  Rent, purchase, start or not.
First, you need a permitted space. You may be able to start a site with your own materials a lot easier than to try and start a dump site for others. Check out your area and see if there is a loophole or other way of starting with limited volumes.
Secondly, determine your products. Do your homework in your area. What is mulch selling for? Is it natural or colored? Your biggest return will be on the colored mulches. What is the competition? These are all easy questions to answer but you need to take the time to do the research.
Third, determine what equipment you need and what equipment you can rent or subcontract.
The simple answer is this:
·         You need a way of loading and moving materials. This is a must and is very easy to rent a wheel loader
·         Keep your material clean. No inert debris just chips and logs. While chips can be sold or colored as is, it is not very attractive.
·         Subcontract a grinding Service to reduce your materials. Decide if you want a finished product or if you are going to screen the material to size after. While you will have a lot of fines because of grinding the chips, as long as there is limited dirt in the material, you should be fine.
·         Rent a color machine, trommel screen or use the subcontract grinder to color your materials. A trommel screen is very easy to rent, especially in the off season. A Mulch Colorant Company can assist you in setting up any machine to color mulch.
This simple way of starting will help you determine:
·         If you will be profitable?
·         How much material you need to stockpile before subcontracting the grinding?
·         What materials sell quickly and which do not?
·         What other products you can add to your inventory?
What if you were to accept additional yard waste or if you do not own a tree business and were thinking of starting a Mulch site? Most everything would be the same, except a little more permitting to accept materials. I would start the same way and determine what your incoming materials look like before doing anything. A lot of dirt, sand and fine debris come into these types of sites, so screening becomes a must before coloring. But when you do screen, you will have other products to sell like topsoil, fill or compost. Compost returns about one third the dollars as colored mulch, so keeping the woody materials for mulch is your best bet.
This makes a screen more valuable to the operation than a grinder. After screening out the dirt, the screen can be used to screen the mulch product to size and then to color the materials. So the first purchase in this scenario may be a screener rather than a grinder.
After determining your volumes, contract grinding expenses and income, then you can make an educated decision to purchase a grinder. But remember, a grinder payment is about one third of the cost of monthly operations of a grinder. Fuel and wear parts are expensive.
This way allows you to dip your foot into the market without any significant capital expense and decide if this is the correct option for you.
On another note, I was asked if I would do some consulting for a customer. I am absolutely available on a consultation basis and the more volume a customer has, the more money I can save them. Guaranteed. Sometimes you just need to look at things a little differently or have someone else look at them for you to see the obvious. If you are a big Corporate Company in Waste, Composting or Landscape Materials, I can save you millions. If you are a little guy getting started, I can eliminate your growing pains because I have made all those mistakes before and worked twice as hard doing it the wrong way.

Questions? Dave Whitelaw-Grinderguy,

The Grinder Guy says…. I told you so!

                I was speaking with a colleague last month that told me a customer of his, a large bagged mulch producer, purchased a large star screen this year and started screening his mulch to size rather than grinding it all. The customer said basically, screening is the best thing since sliced bread and that the fuel, grinding and hauling costs he is saving is more than he imagined. He said to refer anyone to him that is contemplating screening rather than grinding.
Hello?! What have I been saying for five plus years now? I even coined the phrase, “Screen more, Grind Less.” I sell grinders, but I can’t talk enough to sell the difference in operational cost now that fuel is $4 a gallon as a norm.
So what does screening really save you? Here are a few big cost savers:
·         Fuel- Obviously the biggest cost difference. 2 gallons an hour for a screener compared to 50 gallons an hour in some grinders. Save $150-$200 an hour? Who doesn’t want that?
·         Wear- Small screens in a grinder equals more wear and more wear parts
·         Production- Depending on what you are screening and grinding and what with, you could produce more yards an hour with a screen
·         Since you are grinding less, you have more grinding time available for projects and contract jobs. With less grinding needs, that means less overtime for the operator AND your mechanic.
So, what screen do you need and what do you need to do?
Star Screen- Best Option. Today’s star screens are not like the star screens of old. Try one. Sizing is determined by the size of the stars, the spacing between the stars and the speed of the star’s rotation. With an electric motor drive, the range of product size is incredible. A standard deck could potentially screen from ¼” to 1 ¼” and any size in between. You would need about 8 trommel drums to produce the same range of product sizes. Hydraulic drive machines still offer adjustability, but nowhere near the electric drive units. Being able to adjust at basically 1/8” increments, you can maximize production, maximize removal of finished product size materials from feedstocks and produce a perfect quality end product.
Trommel- Good Option. Everyone has a trommel or you can rent one tomorrow. Screening with a trommel works great for wood, compost, mulch and dry materials. The one issue is that you will get some spearing of oversize materials with a trommel drum. How do you avoid this and produce a quality product?
·         Use a trommel that has a level, horizontal drum with spiral flighting inside to roll the materials over the hole in the screen rather than dropping it through like a trommel drum that is on a decline from front to back.
·         Use a smaller screen, at the end of the trommel drum, than is at the beginning and middle of the trommel drum. Only 50% or less of the material being screened makes it to the back of the drum, therefor creating more opportunities for larger size material to make it through the hole. By downsizing the hole in the screen at the end, a smaller sized material will be produced.
·         Increase the trommel hopper speed so that some of the finish size material does make it into the overs. This will help reduce the amount of oversize product in your finished materials.
·         Increase the trommel drum speed so that some of the finish size material does make it into the overs. This will help reduce the amount of oversize product in your finished materials.
Flat Deck Screens- If you have one and nothing else, it’s worth a try. These are the most difficult machines to use with lightweight materials.
·         Bigger is better- The longer the deck and the wider the deck, the better.
·         Use a Larger Hole- Because of the angle of the deck, you can use a larger hole size than the actual product size you would like.
·         Adjust the throw- Depending on whether you would like the material to roll across the hole or bounce more and drop through the hole, adjust the screen box vibration for more or less throw.
·         Feed Speed- Just like the trommels, increase the hopper speed to put more material on the screen deck and limit the spearing or decrease speed to allow more material to drop through the hole.
This should give you a good start at trying screening over grinding no matter what screen you have.
Here are a few points to consider or issues you will discover:
1.       Obviously, different materials will give you different size materials with the same screen on a grinder. On a recent demonstration, once ground logs, brush and landclearing debris produced 50% to 66% of finished mulch size material when screened through a star screen. But the once ground pallets only produced about 33% finished product size material. Consider using a different size screen for your grinder on the initial grind with the materials you are grinding. This will maximize your screening production.
2.        Since you are screening after the initial grind and not regrinding, you are naturally going to have less fines in your product
3.       For those that are currently just dropping out the fines from their mulch with a screen, consider using a double deck screen. Then you could grind with a larger screen and scalp a small percentage of overs while you are dropping out the fines. This will reduce fuel and grinder wear, produce fewer fines, reduce product loss and decrease the bulk density which is great in the bag and on the truck.
4.       Depending on the size of your grinder and screener, you may be able to grind right into a screen because you are only screening out 50% or so of the material.
Finally, before you say you don’t have the money for a screener let’s do the math:     
·         Regrinding mulch uses 100% load on any engine. If it doesn’t blow up, it will use max fuel. A 12 cylinder grinder will be in the 50gph range. An electric generator screen will use about 2gph.
·         Since these are max ratings and 48 gph is the difference, we will use only half, 24 gph, and we will consider equal production for this exercise. These are just rough numbers but easy for you to sub in your own true costs, estimates, etc.
·         24 gallons per hour at $4 per gallon is $96 per hour in savings. Do you regrind 1000 hrs. a year? That’s $96,000 a year. If you only reground 500 hrs. it’s still $50,000 and we cut our fuel savings in half for this example. If we used the full 48 gallons that would be $200,000 a year. This doesn’t include any wear parts or other operational costs like the $300 a week in air filters.
Use your numbers and calculate what kind of savings you can assume.
So, you already have the money, but instead of paying a Lender, you are paying your Fuel Man, Parts Man, Service Man, Operator………….

Dave Whitelaw- Grinder Guy

Help Wanted: Hey Grinder Guy, where have all the mechanics gone?

  Like many Construction Companies and Construction Equipment Sales Companies, I am looking for mechanic also!
With the advent of computer controlled engines, diagnosing engine problems have become much easier. But just because someone can operate a computer, doesn't make them a Technician or all the teens and preteens would be mechanics.
  The Diesel engine has been the same since 1892*. What has changed is the controllers. Computers now control everything from the fuel and air, to the emissions at the end. In addition, the equipment is controlled by a separate software.
So what does all that mean?
- The engines are much more technical than just 20 years ago.
- Technicians need much more electronic knowledge than in the past.
- Computer Training is a requirement for engine service these days.
As a result, there are fewer and fewer Service Technicians available.
So what can you do?
- Take advantage of any free trainings available from Equipment Manufacturers. On a typical sale, my company spends 1-5 days for equipment and service training on new and used equipment. A follow up visit usually occurs 2 weeks or a month later with ongoing courtesy visits made when possible.
- Schedule a paid training for specific engines or machinery that are common to your operation or that are difficult to get timely service for.
- Purchase specialty tools and equipment to reduce the need for service calls. This includes engine software. I carried my own Engine Software computer for years just so I could help my customers avoid waiting for a Service Technician to show up. As I recall, the hardware and software was only $1200 to purchase. It is available right from your Equipment Dealer for any customer. It is not the full software version that a Dealer would carry, but it is plenty powerful enough for you to diagnose engine issues and codes and save you many hours of downtime waiting on a service call.
- Purchase a remote monitoring software that gives you and your Dealer or Manufacturer the ability to remotely diagnose equipment issues without having to visit your site.

So are you looking for a service tech job? Or know someone who is? We are a small industry and need to help each other out.

- Experienced Service Technician position available. Travel throughout the US and Canada servicing, installing and operational training of Recycling Equipment. Location: Denver, CO or potentially anywhere in the Continental US. Salary- Negotiable. For more information call me, 813-421-2757.

- Experienced Service Technician position available. Service, installation and operational training of crushing, screening and composting equipment. Travel via a Service Vehicle throughout the State. Location: Florida  Salary- Negotiable. For more information call me, 813-421-2757.

I also have a customer looking for a knowledgable Grinding and Screening Operations Foreman and have an Equipment Sales position available.
Looking for a someone? Need Someone.
Dave Whitelaw

*- Wikipedia

Hey Grinderguy, how does a star screen work?

Star screens are getting more and more popular since most of the issues of the star screens of the past, have been resolved. Star screens are pretty simple and similar to a disc screens.  So how do they work?
1.       Rubber stars have a hole in the center and are slid over a shaft
2.       The ends of the shafts have bearings and one end has a sprocket.
3.       Shafts are aligned so the stars on one shaft go in between stars on the next shaft
4.       A chain ties the sprockets of each shaft together with an electric or hydraulic motor for power
5.       These shafts rotate at basically the same speed in the same direction
6.       The rotating stars actually move and carry material along the top of the stars, from one shaft to the next,  until there are no more shafts left
7.       The amount of shafts and the size of the stars vary
So, where does the screen come in?
·         The space between the stars actually determines the range of particle size
·         The speed of the stars rotating on the shaft creates the actual particle size
·         The slower the rotating shafts, the more time and opportunity material has a chance to fall through the gap between the stars
·         The faster the stars rotate, the faster the material moves across the top of the stars, the finer the particles that actually make it through between the stars
·         So, a single star deck can produce multiple product sizes and all dependent on the space between each star on a single shaft and the speed of rotation of the stars
For example, a 1” space between stars, with ½” wide stars, could produce ¼” , 1 ¼” material or any size in between. This is because the star rotation speed is moving the materials across the top and the other shafts have a star splitting the 1” gap with another ½” star.
So why are they becoming more popular?
·         Because the stars are flexible, they are able to limit the amount of buildup from wet materials, giving the ability to produce much more than a traditional screen in wet moist applications.
·         With many mulch operations removing the fines from their product, the range of product sizes available from the star screen is advantageous, and the production is much greater than a trommel screen. You can just remove fines, or scalp overs with the same deck
·         Heavier materials work well, like soil blends, but no aggregates, as they will wear away the rubber stars.
So, what do you do?
·         Try one in your applications
·         Stationary electric decks are relatively cheap compared to a portable machine
·         Electric drives are better than hydraulic drives because the ability to adjust speeds is much greater in an electric motor because of the much higher rpm
·         Find a machine with some kind of cleaning system. You will get buildup but with a cleaning system, you will not.
·         If you have a contaminants problem, paper, plastic, stone, find a unit with an inert material removal system or stone separator
·         There are many 3 product machines on the market that can remove dirt and scalp overs at the same time. What can that do for your business?
Operational cost is always a concern. While there are a lot more moving parts, the production difference in most materials more than makes up for the additional maintenance costs.
How do you know? Try it, there’s no better way.

Hey Grinderguy, do I need a Windrow Turner?

                If you are new to the composting industry, you are probably wondering what, when and why compost operations use windrow turners. Whether you are composting yard waste, food waste or sludges, a windrow turner is an essential part of composting material but not necessary in every case.
                Composting takes water and oxygen in an open air environment. We can get technical and discuss carbon and nitrogen levels, but regardless of that, you need water and oxygen.      
A windrow turner is used to aerate a compost pile, mix materials, apply liquids and to generally loosen material in a windrow. The more oxygen, the more the materials heat up and start the composting process. Pretty simple. Just like your leaf pile in your back yard.
In general, in a food waste or municipal sludge application, it would be very difficult to convince me of a reason not to use a windrow turner. The mixing action of a turner and the ability to provide oxygen to all the material in the compost pile is something you cannot do efficiently with a wheel loader. Having the ability break up heavier materials like sludges, and break apart food waste particles, is just something you cannot do with a wheel loader.  These heavier, wetter materials tend to block any airflow through the windrow. The more airflow, the more oxygen, the hotter the pile, the more composting of materials.  This means a faster compost process. If you are short on site space, the faster the composting, the more material you can compost. A windrow turner provides adequate air flow into the materials and increases the porosity of the pile by loosening the materials. Without the oxygen, piles will turn anaerobic and create enough odor that neighbors in the next county will be complaining.
When it comes to yard waste composting, the materials are generally loose to begin with, so turning with a loader is generally sufficient. The problem comes when you get to 25,000-30,000 ton per year. With that volume of material, you need to speed up the process and compost faster. With that much material, you can keep a windrow turner busy and do a much better job of aerating the windrows than a wheel loader. This will help speed up the process and produce compost in probably half the time as just bucket turning with a wheel loader. It will also save you a lot of site space because a wheel loader needs to get in between the piles to turn the windrows when a straddle Windrow Turner doesn’t. Piles can run together at the edges with some Windrow Turners.
So do you need a Windrow Turner?
·         What type of materials are you composting?
·         What volume of materials are you composting?
·         What kind of site space do you have?
·         Do you need to apply water or liquids to your windrows?
These questions should answer everything for you.
There are different types of Windrow Turners. Pull behind type which is towed by a tractor for example, and operate alongside the tractor and straddle type that sits atop a windrow. The straddle type Windrow Turners are able to turn larger windrows and turn heavier loads. The pull behind type is fine for small windrows and startup operations.
                So what do you look for in a Windrow Turner?
·         Define your volumes and decide which type will work best.
·         If you are short on site space, look for a unit that can turn windrows that are inches apart. This saves and incredible amount of site space.
·         Look for one that can apply liquids while you are turning. Yard waste compost will compost much more quickly when you are adding water to them.
·         If you are composting sludges and food waste, look for some kind of air filtration system for the operator cab. Ammonias and other chemicals build up in windrows and the air quality inside the operator cab may be contaminated.
·         Match the windrow width and height to the Windrow Turner size
·         Look for a unit that will turn the entire windrow not that just rototills a pile. Lifting and piling will generate the most porosity to the pile.
·         Ask about options like scraper devices, windrow displacement and tracks or tire drive.

While this is just a general outline, it should put you on the right path to your needs.

Questions, Dave Whitelaw

Hey Grinder Guy, who makes the best wear parts?

It seems there are more and more companies offering wear parts for grinders and chippers these days. There are some common parts that are interchangeable, but most are specific to each machine. When aftermarket companies reverse engineer these products, you may not get the same fit or quality. If the parts are cheaper, there may be a reason other than less markup.
Most wear parts sales are through Dealers of these products. All that inventory has a cost and that cost is passed down to you. But remember, those parts are available very close to you and it is not the parts that cost you the most money, it’s the machine downtime.
In most advertisements, the cost of grinder tips are usually emphasized. This can be deceiving. Are these wear tips the same as the ones you are using and five dollars less each? Chances are not. Here’s where they may deceive you:
·         All wear parts are different, but most everyone uses some sort of replaceable tip that is impregnated with tungsten carbide chips for longer wear life.
·         Tungsten Carbide, or Carbide as it is commonly called, is a combination of Tungsten and Carbon*. A Carbide impregnated surface (or coating) provides a greater wear resistance than the base steel that the wear parts are made of.
·         The less carbide, the less the cost of the tip. You generally are paying by the inch of weld. Today’s cost is about $2 a square inch of weld. That is just the material.
So the cost of the tip may be cheaper, but the wear may not be the same.
A real wear parts company will take the time to explain how much carbide is applied and type of steel you are receiving. Ask questions. These people are full of information that may help you when you tell them what type of grinder you have, what you are grinding and what product you are looking for?
So how do you save money?
·         Try some new tips. Run a few side by side with what you have currently.
·         Purchase larger quantities. Without the Dealer having to stock those quantities, you should get a price break.
·         Your freight cost may be only 20%-30% higher for 2 sets instead of one. What does that do for your cost per tip?
·         Check your tips. Are you using all the carbide surfaces before replacing the tip?
·         Buy a different tip with less carbide edges. You may get the same wear for less of a cost
·         Carbide is more brittle, and will break off or chip off wear part surfaces when it impacts solid objects like rock or steel. So maybe less carbide on the face and more on the sides gives you more longevity.
The point is, give some other parts a try and see what it does for you.
The only thing you get while standing still, is passed.

Questions? Dave Whitelaw